Matched, Unmatched and Partially Filled Orders in 2026: What Happens at Game Start

The quick answer

• Matched (filled): your order traded against someone else's. You hold a position.

• Unmatched (resting): your order is sitting on the order book at your price, waiting for someone to take it.

• Partially filled: part of the order traded and the rest is still resting, or was canceled.

• Canceling: you can cancel any part of an order that hasn't traded. What already filled stays filled.

• At game start on Novig: open pre-game make orders cancel automatically when the game goes live.

• At game start on Kalshi and Polymarket US: their published docs describe no automatic cancel at the start of play, so check your open orders yourself.

A position on a prediction market is the part of your order that filled. A partial fill leaves you holding fewer contracts than you planned, and if that order was one leg of a hedge or an arbitrage, the two legs no longer cover each other.

On Novig, topping up a partial fill before the game carries no fee; once the game starts, taking the rest carries a taker fee.

What matched, unmatched and partial mean

"Matched" and "unmatched" are Betfair's words, and US prediction markets use "filled" and "resting" (or "open") for the same states. Polymarket US lists the full lifecycle: pending, open, partially filled, filled, then canceled, expired or rejected.

An order only becomes a position when it trades. Novig's help center describes the two ways in: a take order "executes immediately at the displayed price," while a make order "goes into the market and waits for another user to accept the other side."

A take order bigger than the size at the best price fills part there and part at worse prices. Kalshi's example is a quick order for 1,000 contracts against 500 offered at 10c and more at 12c, which fills at an average of 11c. A make order can also be partly taken, with the rest left resting.

How we checked

Every rule below comes from the venue's own pages, opened on 6 October 2026 and rechecked on 7 October: Novig's help center and the Ludlow Exchange rulebook (version 1.3, posted 2 September 2026), Kalshi's help center, fee schedule and API documentation, Polymarket US documentation, and Betfair's help center for the original vocabulary. The worked example uses illustrative prices and is computed to the cent.

How orders queue and fill

Novig and Kalshi both document price-time priority. The Ludlow rulebook, which governs Novig, says "Orders at a better price have priority over Orders at inferior prices. Among Orders at the same price, Orders are executed in the order in which they were received." Fills happen on an "or better" basis, so a limit order won't trade at a worse price than the one you set.

Time-in-force decides what happens to the unfilled part:

For the partial case, the rulebook says a good-until-canceled order that partly fills "remains in the Order Book until the remainder is filled or the Last Trading Date and Time of the Contract." In the Novig app, a make order carries a timer that you'll set before placing it.

Canceling an order

Any unfilled part can be canceled. Novig's rulebook also warns that "the Order may be executed before Ludlow is able to cancel it. If an Order has been filled in whole or in part, only that portion of the Order (if any) that has not been executed may be canceled."

Canceling is free on Novig and Kalshi. Novig's fee page says "There is no fee for placing, modifying, or canceling an order that never fills," and Kalshi says "there are no fees associated with canceling a resting order."

Partial fills also change what you pay on Novig. If part of your order fills immediately and the rest fills later from the book, "you only pay the taker fee on the portion that is filled immediately, if taker fees apply for that market." On a pre-game straight trade there's no fee on either part.

What happens to unmatched orders at game start

Per Novig's help center, a pre-game make order cancels "when your set duration expires, OR when the game goes live," and "Even if your duration extends past the scheduled start time, the order cancels automatically when the event begins." Novig may also mark a game live before its listed start, and "When this happens, all open pregame make orders are cancelled."

Kalshi's API documentation says a market's close time "may be set well into the future to allow for rescheduling," so a market doesn't have to close at kickoff. Resting orders are canceled shortly after the market closes, and all resting orders are canceled when a paused market is reactivated. API users can also flag an order to cancel if trading is paused.

Polymarket US applies its sports rules "to both pregame and in-game trading." Neither Kalshi nor Polymarket US documents a cancel at the start of play, so review your resting pre-game orders on both before the game starts.

Betfair used to cancel every unmatched bet when a market suspended at the off, and now lets customers choose "Keep" so a bet persists in-play.

A partial fill, worked through

Say you spot a gap on an NFL game: Team B at 52c on another venue and Team A at 45% on Novig. You buy 400 Team B contracts elsewhere for $208 and post a Novig make order for 400 Team A at 45%, with a two-hour timer. Both legs filled would cost $388 and pay $400 whichever team wins, $12 before any fee on the Team B leg.

Only 150 Team A contracts fill before kickoff. The game goes live, and Novig cancels the other 250.

The arb is now a $124.50 lean on Team B. To close it you'd need 250 more Team A contracts, and the price has moved to 48% in-game. Taking them costs $120.00 plus Novig's live taker fee of 0.03 x 0.48 x 0.52 x 250 = $1.87. The Team A leg now totals $67.50 + $120.00 + $1.87 = $189.37, both legs cost $397.37, and the position pays $400 either way, $2.63 before the Team B fee.

The partial fill cost $9.37 of the original $12 edge: $7.50 from the 3c price move and $1.87 in Novig's in-game taker fee. A top-up before kickoff would have carried no fee.

What to look for

• Fill status: check filled and remaining size on both legs before you treat a hedge as done.

• Game-start rule: know whether your venue cancels resting orders at the start of play or leaves them live.

• Time-in-force: use fill-or-kill where a partial fill would leave you exposed, and good-until-canceled only on orders you'll watch.

• Fee timing: on Novig, finish pre-game positions before kickoff, when taking carries no fee.

• Cancellation race: a cancel only removes what hasn't traded, so check the fill after you cancel.

Order FAQ

What happens to unmatched bets when the game starts?

It depends on the venue. Novig cancels open pre-game make orders when the game goes live; Kalshi's and Polymarket US's published docs describe no automatic cancel at the start of play.

What is a partially filled order?

A partially filled order has traded for some of its size, with the rest still resting or canceled. You hold a position only in the filled part.

Can I cancel a partially filled order?

You can cancel the remainder that hasn't filled. The filled part is a position, which you close by selling or holding to settlement.

Is there a fee to cancel an order?

Novig and Kalshi charge nothing to place or cancel an order that never fills.

Sources

All opened 6 October 2026 and rechecked 7 October 2026.

Novig, "Make Orders vs. Take Orders and How Order Timers Work": support.novig.com/en/articles/10715726

Novig fee schedule: support.novig.com/en/articles/16195057-fees-on-novig

Novig, "Valid Make Order Prices and How They're Determined": support.novig.com/en/articles/15554753

Ludlow Exchange, LLC Rulebook v1.3 (posted 2 September 2026), Rules 5.2(c)-(d), 5.4(e), 5.6, 5.7(a), via support.novig.com/en/articles/16075446

Kalshi help center: Quick Orders; Limit Orders; Fees

Kalshi fee schedule: kalshi.com/docs/kalshi-fee-schedule.pdf (effective 7 July 2026)

Kalshi API documentation: Market Lifecycle; Create Order (V2)

Polymarket US documentation: Orders & Trading; Sports FAQs

Betfair, "Exchange: What are the options 'Keep bet' and 'Take SP' when I have an unmatched bet?", support.betfair.com/app/answers/detail/a_id/415